Definition

Secondary parkinsonism is when symptoms similar to Parkinson disease are caused by certain medicines, a different nervous system disorder, or another illness.

Parkinsonism refers to any condition that involves the types of movement problems seen in Parkinson disease. These problems include tremors, slow movement, and stiffness of the arms and legs.

Alternative Names

Parkinsonism - secondary; Atypical Parkinson disease

Causes

Secondary parkinsonism may be caused by health problems, including:

• Brain injury
• Diffuse Lewy body disease (a type of dementia)
• Encephalitis
• HIV/AIDS
• Meningitis
• Multiple system atrophy
• Progressive supranuclear palsy
• Stroke
• Wilson disease

Other causes of secondary parkinsonism include:

• Brain damage caused by anesthesia medicines (such as during surgery)
• Carbon monoxide poisoning
• Certain medicines used to treat mental disorders or nausea (for example, metoclopramide and prochlorperazine)
• Mercury poisoning and other chemical poisonings
• Overdoses of narcotics
• MPTP (a contaminant in some street drugs)

Symptoms

Common symptoms include:

• Decrease in facial expressions
• Difficulty starting and controlling movement
• Loss or weakness of movement (paralysis)
• Soft voice
• Stiffness of the trunk, arms, or legs
• Tremor

Confusion and memory loss may be likely in secondary parkinsonism. This is because many diseases that cause secondary parkinsonism also lead to dementia.

Exams and Tests

Your health care provider will perform a physical exam and ask questions about your medical history and symptoms. Be aware that the symptoms may be hard to assess, particularly in older adults.

Examination may show:

• Difficulty starting or stopping voluntary movements
• Tense muscles
• Problems with posture
• Slow, shuffling walk
• Tremors (shaking)

Reflexes are usually normal.

Tests may be ordered to check for other problems that can cause similar symptoms.

Treatment

If the condition is caused by a medicine, your provider may recommend changing or stopping the medicine.

Treating underlying conditions, such as stroke or infections, can reduce symptoms or prevent the condition from getting worse.

If symptoms make it hard to do everyday activities, your provider may recommend medicine. Medicines used to treat this condition can cause severe side effects. It is important to see your provider for check-ups. Secondary parkinsonism tends to be less responsive to medical therapy than Parkinson disease.

Outlook (Prognosis)

Unlike Parkinson disease, some types of secondary parkinsonism may stabilize or even improve if the underlying cause is treated. Some brain problems, such as Lewy body disease, are not reversible.

Possible Complications

This condition may lead to these problems:

• Difficulty performing daily activities
• Difficulty swallowing or eating
• Disability (differs from person to person)
• Injuries from falls
• Pneumonia from breathing in saliva or from choking on food
• Side effects of medicines

Effects from loss of strength and mobility (debilitation):

• Breathing food, fluid, or mucus into the lungs (aspiration)
• Blood clot in a deep vein (deep vein thrombosis)
• Malnutrition

When to Contact a Medical Professional

Contact your provider if:

• Symptoms of secondary parkinsonism develop, come back, or get worse.
• New symptoms appear, including confusion and movements that cannot be controlled.
• You are unable to care for the person at home after treatment starts.

Prevention

Treating conditions that cause secondary parkinsonism may decrease the risk.

People taking medicines that can cause secondary parkinsonism should be carefully monitored by their provider to prevent the condition from developing.

References

Fox SH, Katzenschlager R, Lim SY, et al; Movement Disorder Society Evidence-Based Medicine Committee. International Parkinson and Movement Disorder Society evidence-based medicine review: update on treatments for the motor symptoms of Parkinson's disease. Mov Disord. 2018;33(8):1248-1266. PMID: 29570866 pubmed.ncbi.nlm.nih.gov/29570866/.

Jankovic J. Parkinson disease and other movement disorders. In: Jankovic J, Mazziotta JC, Pomeroy SL, Newman NJ, eds. Bradley and Daroff's Neurology in Clinical Practice. 8th ed. Philadelphia, PA: Elsevier; 2022:chap 96.

Ostrem JL, Okun MS. Parkinsonism. In: Goldman L, Cooney KA, eds. Goldman-Cecil Medicine. 27th ed. Philadelphia, PA: Elsevier; 2024:chap 378.

Pringsheim T, Day GS, Smith DB, et al. Guideline Subcommittee of the AAN. Dopaminergic Therapy for Motor Symptoms in Early Parkinson Disease Practice Guideline Summary: A Report of the AAN Guideline Subcommittee. Neurology. 2021 Nov 16;97(20):942-957. PMID: 34782410 pubmed.ncbi.nlm.nih.gov/34782410/.